Cable construction



Sept. 10, 1929. w, TES

CABLE CONSTRUCTION Filed Aug. 1, 1925 2 Sheets-Sheet p 9 B. w. GATES CABLE CONSTRUCTION 2 sheei eet 2 Filed Au 1, 25

REVOLVING F AME m a w iii 4 Ravoumw RAME Patented Sept. l0, 1929.

BERNARD w. GATES, or PLEASANTVILLE, new YORK.

CABLE cousmnuorron.

Application filed August 1,1925. Serialll'o. 47,492.

This invention relates to improvements in cable construction. More particularly it relates to the filling of interstices between the circular strands composed of the separate electrical conductors of the cable and the circular case or. sheathing which encloses the group of strands.

Having already pointed out the advantages of using paper for this filling, in my 1 Patent 1,169,949 of. February 1,1916, where I show the paper filling material in the form of a twisted strand, or a plurality of such strands twisted together to form a cord, it is an object of the present invention to make an improvement over what is there disclosed. Although paper is relatively soft, spongy and elastic, so as to be good material for a cable filler, it has not heretofore been found commercially possible to pack it into the cable sheath as tightly as is desirable. In the case of paper cords such as are shown in my said patent this is because those cords, which are intended to fill the lunar spaces between the strands and the enclosing sheath are themselves substantially circular and therefore cannot pack tightly into these spaces, which are triangular with curved sides and sharp pointed corners. These cordsare therefore inherently incapable of filling thelunette shaped spaces, except by the insertion of an indefinite number of strands, arranged in progressively smaller sizes for the horns of the lunettes-an arrangement which is commercially impracti cable. Nor can they be deformed as they are laid, so as to fit the shape of the space that-is to be filled, for the paper in each cord or strand is locked in its circular form by its twist.

The present i invention whereby the advantages 0 paper may be enjoyed, and yet vthe horns as well as the broader parts of the lunettes be substantially filled with paper under such reasonable comp ression as is desired, all by feeding the paper in one large sliver for each space as the cable is made. Such sliver may contain or be accompanied by a core or strand of 40 fprovides means vcheaper material, such as'jute, if desired;.

and, although jute is objectionable as being irregular in size, relatively non-elastic, and difiicult to pack nevertheless the elastic filling of the invention can accommodateitself to the jute as well, and by its elasticity and expansibility can make a solid pack not-' withstanding that it is itself prepared of uniform stock while the jute is not. These new results are attained by making the filler for each lunette of one or more strips each of which is so folded and crumpled laterally, that when placed in the cable spaces it tends to expand, and thus to shift its position and shape laterally, to the extent ermitted by the walls and by the other ing of the lunette. Preferably the crumplings are made in the paper strip before it is put into the cable, but this is notessential, for the crumpling can be done as'the strip becomes associated with the "other elements of the finished cable. When the paper fillin is prepared beforehand it is a feature to 0 m the individual thread somewhat elliptical or fiat, in its crumpled cross section. It is another feature to arrange a plurality of such in a group, which group is inserted as a unit sliver, the individual threads of which at thetime of insertion can spread out sidewise over each other, thus to distribute themselves or parts of themselves into the horns of the lunettes.

In the formation of a cable the strands,

usually three, previously prepared with a multiplicity of conductors in each, come together with the strips of paper that are to form the filling positioned between the strands, and all are twisted together and drawn through a die with roundrholes of proper size and location to control the twisting and give the desired compression of filling. The filling threads in each group of sliver adjust themselves in position so as-to fill the available space between conductor strands and wall of die with approximate uniformity, assuming the positions of least resistance or pressure; and because of the flattish shape and laterally crumpled character of cross section of the individual filling threads, such threads are able to occupy the thinner parts of the space. The omnipresence of the crumples throughout the space,

. and the tendency to expand, roduce "a general filling of the space and u iquitous support for the cover which is to be wrapped around the cable as it comes from the die, more perfect than any heretofore known to me.

The invention is applicable also to cables or cords wherein conductors are laid parallel and are covered with any sort of covering, as for example, by braided cotton. In all such cables it is a further feature that part of the filling or internal wrapping may be printed at some stage before its introduction, thus fixing in the cable any distinctive information that may be desired without the need ofintroducing a separate element in order to do that. And when the filling of the invention is used for caulking car doors, as hereinafter suggested, the pres-v ence of such printing affords a guarantee to the consignee and the carrier that the original filling has not been removed by a thief and replaced by a counterfeit.

The individual threads may be made in several ways, one of which here illustrated, by drawing a flat strip of paper of any suitable width over a roll, rod or the like which stabilizes a cross sectional portion of the onward moving strip, and thence leading it through a small hole, comparable to a die, of diameter equal to a small fraction of the width of the strip.v In passing from the stabilized cross section point to the die one or both edges of the paper curl inward. Assuming that the axis of the die hole is in the medial plane through the supply roll of paper, perpendicular to its axis,

both edges curl inward, each edge preferably forming itself into several convolutions with hollow interior. This makes a double tube formation, whichis attained as the die is reached, and these two tubes, thus lying side by side at the axis of the strip are then crushed together as the die is entered, with pressure inward in all directions, with the formation on all sides of deep wrinkles which extend longitudinally. If it is not to go forthwith into the cable, the paper issuing from the die may be creased sufficiently to remain' in this crum led state by passing it around a fairly a rupt corner under'the same tension which is drawing the strip forward, after which the strip -may be wound on a spool for storage until it is ,to be inserted in the cable. In a preferred form of the invention a group of such strips each of which is herein for convenience called a thread are wound together as one, all of them going together through a single thread guide to the spool or tube on which they are being wound. When the cable is made this group of strips, herein considered to constitute the sliver is laid in the interstices between the conductors and the sheath. The mechanism for supplying the sliver to the cable making die can be simpler wh ere the threads are thus fed; as a sliver, but whether thus fed or fed singly as threads which become grouped first at the cable die, the threads individually can work their way into places and fill parts ofthe spacesbetween conductor strands and cover where resistance and )ressure are least. They are able to do this ecause the individualsof the group are not tied to each other and moreover, are practically flat, so that they can slip over each other sidewise. 'As compared with the previous types of filling, in which the paper is twisted, the filling of the invention is superior either when used in grouped form or when used in single strip form, for in either case it can expand more or less due to the inherent elasticity of the paper and the fact that it is compressed laterally along parallel lines so that no part of the paper exerts tension in such direction as to prevent either its own expansion or the expansion of other parts. Because of the flatness the tape is able to enter more deeply into the horns of the lunettes; and where a group of strips'are laid in together the individuals of the group have even greater freedom of lateral moving to find their ultimate resting places in the interstices. The group can be produced at a single operation at approximately the same cost as a single P large sized strand of twisted paper filling and can be handled as a single strand; and therefore can be used with an equal economy of space and convenience on the cable making machine. The invention can be applied in various ways and it is intended that the patent shall cover whatever features of patentable novelty exist in the invention disclosed.

Illustrative embodiments of the invention are portrayed diagrammatically in the accompanying drawings, in which Figure 1 is a perspective indicating the making of a strip of paper into a single thread for the filling;

Figure 2 indicates the making of a group of such threads and the winding of them as a single unit or sliver;

Figure 3 indicates the making of a cable in which the filling threads of the invention be of such width as is desired to be 'in-- corporated in an'indi'vidual thread 20 of the filling. This roll rests on bearings 11;

and the brake 13 makes the tension to which the strip 12 is subject, on being drawn from the roll 10 up around rod 14 and thence through the relatively small die hole 15, to a winding machine 17 of any suitable type where it is wound on tubes or spools 18. The edges 20 of the strip gradually curl inward as they approach the die, making two tubes of paper which are crushed in going through the hole and by the edges of the plate at-the hole, over which the strip runs asv it enters and as it leaves, because the die plate 16 is set oblique to the line of draft of the paper strip. This makes wrinkles'in the strips,'which extend longitudi -z. 'nally and which owing to the inherent elas ticity of the paper tend to spring open laterally. The drawing of the strip over the rear edge of the die hole, under tension, tends to make the resulting crumpled strip somewhat thin and relatively broad in its total cross section. 4 This makes what is herein referred to as a 'single thread because it functions as an indivisible unit, although it will be observed that in dimensions it does not have the small size the term thread usually signifies. For example, a

strip of paper 8 inches Wide may make a thread Wide and thick, as wound on its spool under moderate tension.

Several of these supply strips and forming dies may be grouped together as in Figure 2, with the thread product of them all going as a group to a winding guide 21 and thence issuing unitedly as a sliver 23 to be wound as a group or unit on the tube 25.

When these are introduced into the cable they may be inserted in the manner which is already customary, but they are capableof re-distributing themselves and shifting their positions relative to each other as they go in, so that they substantially fill the spaces between strands 28 of grouped conductors, as seen at in Figure 4.

In Figure 3 some of-the spools 18 may be considered as holding jute 19 or other low cost filling as now customary. This being run in with the paper, its irregularities of thickness are compensated by the elasticity of the paper.

In Figure 4 the jute is represented at 19.

in the midst of the paper.

The assembly 30 of conductors 29 and filling 20'issuing from-the die in this stage of completion is then wrapped with narrow strips of paper 46, or is otherwise covered in order to bind theassembly together and to hold the shape and position of the cable parts until it shall receive its sheathing of lead 46 in a subsequent operation.

It is not necessary that the characteristic crumpling of the paper filler be made before tively by the use of such a preliminary die as described, toform it from its flat strip shape into the crumpled thread shape,

rather than by merely relying ,upon the occurrence of the-crumpling as a strip enters the cable from a spool where it has been in fiat form. The latter, however, serves very well for filling the central cavity between strands. In Figure 5 is shown an arrangement of apparatus for making the filling of the invention at less expense than the arrangement indicated by Figures 1, 2, and 3. The spools 40, corresponding to the spools 10, have a fiat strip of paper 32 which passes over a rod 34 and through a die plate 36 having a hole which constitutes a supporting guide near the cable die and pro- 'duces the same crumpled effect as do the.

die plates 16 .and hole 15; and from each such point of support the strip may go directly into the space in the cable between the cover and the strands of conductors, with the same effect as if it had been preliminarily wound on a separate spool 18, shipped to the place of use, stored till wanted, and then fed from a revolving frame into the cable.

be omitted and the paper drawn directly in flat form as at 32' from supply'rolls 40 mounted onthe rotating frame into the as sembly dies 26 where it will crumple itself laterally in wrinkles which tudinally so as more or less to the spaces between the strands This arrangement is especially suitable for filling the space in the centre. Even in this case, while the flat strip may if desired be led direct to its position of final occupancy yet the shaping of the filling to fit the space will be helped if the flat strips are passed together through a ring which assembles .them loosely and guides them in unison.

When the pro-crumpled strip 20 has been wound on a spool it becomes rather flat; but any one can be restored to roundish shape if desired or thought necessary by passing it through a suitable die just before it enters the cable; or it (or several grouped in a sliver) can be. made into any particular shape to approximate the shape of the particular space into which it is desired that this particular sliver or strip shall fit. In the preferred form of the in vention illustrated in Figure 2 a considerable number of ends 20 run through individual dies 16 so that each strip is crumpled laterally and then all of this group are fed together through a single thread guide 21- to wind them as a single group on one tube or spool. In this formation the foldings and the relation of the individual strips tend longi- However, if preferred, the dies 35, 36, may

to each other are all those of parallelism.

-When multiple-end filling has been used before, so far as I am aware, both it and its individual threads have always been twisted, but I have discovered that the parallel laid threads pack better and have ends separately, i. e., on separate tubes, for

supply to the cable machine. This has the further advantage that as there is a lack of space on the cable making machine, by

this method the available space is utilized more efliciently. If it were desired the individual threads which go together'to form the sliver might be held together by serving them with a light thread, which would break under the pressure applied in the cable die Where the paper threads have to adjust themselves to position to fill places, and yet would be strong enough to hold them together until they thus enter. In practice this does not appear necessary; but after the formation of the cable in the die 3 it is customary and advisable to hold the whole in its shape by applying a serving of cotton string or paper strips for reliance until the lead sheath is applied.

The invention thus produces a filling which is absorbent of the insulating composition that. is customarily applied later, and which comprises substantially a homogcnous mass of expansible nature. The cxpansibility results from the parallel crumpled ("character of the filling. This gives. greater opportunity for part of any particular thread to move sidewise, at any particular. place therein where it may hap pen that pressure tends that way, as for eX-.

ample where there is a lump or irregular place in some jute filling incorporated along with .it. Of, if the threads. as they enter.

are not in precisely the form to fill the 'shape, as they rarely will be unless a die is made for that express purpose, the pressure which occurs in one part or another 'of the space can force some of them sideways into the less densely occupied space, thus producing a uniform filling and uniform support for the soft lead covering which is to follow, outside of the strands and filling. As applied for filling spaces in cable and as contrasted with the twisted cord formation of paper filling which is the best previouslyknown to me, the fiew construction herein described is superior because of being more spongy and hence filling the interstices more fully. It can be made in continuous pieces of indefinite length, thus eliminating the splices and joints which have been objections in the former style. Owing to the' flatness with which it packs itself onto the tube, when prepared before being put into the cable-making machine, a considerably greater length can be held on a tube of specified dimension, thus reducing the number of shut downs on the cable forming machine which become necessary in order to insert fresh supply rolls of the paper filling. Also the cost of production is materially less, because the forming machine can operate at higher speed than a twisting machine. Where a number of threads are grouped together into a sliver which is wound on a single spool before being put 'into the cable machine,

there is a saving innumber of operations and in handling, making still lower cost of production. And in this case the sliver as a whole will more readily shape itself to go'into the cable, without a special die; and it is susceptible to being shaped by a die if desired, which is not true of a round cord filling where several threads are twisted together.

Another feature which is characteristic of the individual threads when formed preliminarily as described above is that in the formation preliminary to the die each half of the st ip, from-centre to edge, is formed or fcurled into a multi-thick-walled tube;

and when the two tubes are compressed to-' gether in the die, and are wrinkled, some of the wrinkles interlock with each other within the single crumpled thread; .and then when this hasbeen flattened by winding on the spool thefolds become creased so that these interlockings hold the two tubes lightly side by side and prevent'them from spreading or from opening except under pressure or tension. lVhen used for cable filling this interlocking serves no particular function in the cable, and is no detriment, for the two parts can 'expand away from each other laterally in case that becomes the course of least resistance; but if the material be used for some other purposes, as for example, for

caulking a car door, it is an advantage to have this material preserving its uniformity of shape throughout its length, notwithstanding the handling and manipulation incidental to its use. i

Although the invention has been described more particularly as it may be applied in connection with cable filling it is obvious that the filling material above described can be applied for other filling purposes, as for example for cracks where a caulk is desired. One instance of this wiuld be to prevent the means escape of grain through the doors of freight cars.

In Figure 3, which illustrates one method of using the'filling of the invention in the making of a cable, the tubes or spools 18 each carrying a supply of the thread 20 are mounted on a frame 22 which revolves with are the previously prepared strands of electrical conductors that are to compose the cable. A take-up reel 27 draws the assembly of strands and filling through the stationary die plate 26. The rotation of the s ools 28, about the axis of the assembly 30 w ich has gone throughthe die, puts the strands 28 1nto the cable formation while at-the same I time the threads coming from the spools 18,

rotating about the same axis and at the same rite of speed angularly, fill in the spaces between the strands. .This holds becomes gradually contracted and compressed to the round form of the cable, by the tapering form of the hole 24 through'the, dieplate, during which operation the paper filler yields or expands as may be necessary or as it may have opportunity to do, in order to produce the internal condition of uniformity of pressure which tends to be established under such circumstances. i a

In this specification and in the claims the term cable is used in that broad sense in which it is or mayv be used in the electrical industry, wherein a; group of conductors which are to be held together do not necessarily have the characteristictwisted form of a rope or cable used for sustaining tensile stresses. For that reason I include Figure 7 in the drawing which shows a cord or flex ible conduit which is within the class of structures herein called cables because it has two conductors 29 with the surrounding wrapping, 28", which lie side by side in parallelism, with the spaces between their individual covering and the group covering 46 containing the filler 20 of the invention. In this .gcase the exterior covering is represented as being braided cotton. 'lhe printing of any suitable matter on one of these filling slips 20 before it is incorporated in the cable may serve to fix the information contained in the print, which may for example be the name of the manufacturer and the date of manufacture, inseparably with 1 the cable. It will be observed that a part of the contents of the cable is the matter which surrounds the individual conductors in Figure' 7 and this is partly filling and partly wrapping of the conductor, while in Figure 3 they are surrounded partly by the filling and partly by the wrapping 46 of the entire cable. The printed legend, whatever may be desired, may be placed on these fiat surfaces of paper wrapping; but it is less expensive of ink'and cost of doing the printing to place this printing on the filling strips as at the top of Figure 5 which run lineally instead of helically; and it may be placed upon them either before they are assembly, a thing which cannot be done with the frame carrying the spools 28 on which the jute filling heretofore used for this purpose.

In'case the filling curled inward at both edges above described is not desired the fille crumpled as in the case of the doubly curled strip described and illustrated in Figure 1.

I claim as my invention:-

1. A. cable of electrical conductors comprising a plurality of strands of conductors,

a coverin for the whole, and a filling of paper for the spaces between the strands and the covering, said paper being in strips crumpled laterally and free from twist except as they follow the twist of the strands in the cable.

2. A cable of electrical conductors com- ;prising a plurality of strands of conductors,

the covering, said paper; being in strips crumpled laterally, with a multiplicity of fiattish strips grouped between each two strands, overlying each other radially and extending flatwise into the angles between strand and covering.

3. A cable of electrical conductors comprising a plurality of strands of conductors, v

a covering forvthe whole, and a filling for the spaces between the strands and the covering, composed of paper and a substance having irregular contour, said paper being in strips which are elliptical in lateral dimensions.

L A sliverof expansible filling material comprising a plurality of strips of paper, crumpled lndividually in wrinkles which extend longitudinally, which strips are laid in parallelism in the sliver,

5. A strip of filling material comprising a paper strip, loosely crumpled laterally and readily expansible, said strlp being formed in two multiple Walled tubular portions, side by side, having longitudinal wrinkles which interlock with each other and thus hold the two said portions separably together,

6. A strip of filling material comprising a paper strip crumpled laterally and readily 'expansible, said strip having a multiple-wall collapsed tubular construction.

7. A filling strip for a long narrow crevice comprisin a continuous strip of paper arranged su stantia'lly without twist in itself and crumpled laterally into a multiplicity of longitudinally extending wrinkles.

8. A cable of lectrical conductors having as a component part of the cable a strip of paper on which are printed characters relating to the cable; said strip being incorporated within the cable in crumpled form as a bulky filler for space between adjacent conductors-of thecable with such change of form from flatness as is incidental to its functionainthe cable.

Signe 'at Boston, Mass, this twentyfourth day of 'JulE, 1925.

B RNARD W. GATES. 

